import sys
import multiprocessing
from time import sleep


def change_argv(b):
    print("in change argv", b)
    sys.argv[2] = b
    print(b, sys.argv[2])
    sleep(1)
    return sys.argv[2]


if __name__ == '__main__':
    l = []
    pool = multiprocessing.Pool(2)
    for a in ["aa", "bb", "cc", "dd"]:
        r = pool.apply_async(change_argv, args=(a,))
        #r = change_argv(a)
        l.append(r)
    sleep(2)
    pool.close()
    pool.join()
    for res in l:
        p = res.get()
        print(p)
